How do I get ChatGPT to write in a less formal, more human tone?

The quickest way to make ChatGPT sound less formal is to tell it exactly who it's writing for and what the vibe should be, using a specific persona and a clear 'do this, not that' instruction right in your prompt. I've found that vague requests like 'make it casual' don't work well because the AI doesn't know what 'casual' means to you. It might just throw in a few contractions and call it a day. You need to paint a picture. For example, instead of saying 'Write a blog post about gardening,' you could say: 'You're a friendly, slightly sarcastic gardening buddy named Pat who's been doing this for 20 years. Write a blog post about fixing yellow tomato leaves. Use short sentences. Don't use words like 'utilize' or 'cultivate.' Sound like you're talking over a fence, not giving a lecture.' This works because you're not just adjusting a dial; you're giving the AI a whole character to play. The persona (a sarcastic buddy) sets the tone, and the 'don't use' list blocks its default formal vocabulary. Another trick that helps is pasting a sample of your own writing into the prompt first. You can say, 'Here's how I write. Match this tone.' The AI is surprisingly good at mimicking a style when it has a clear example. If the output still sounds a bit stiff, don't rewrite the whole thing. Just reply with 'Shorter sentences. More punch.' and it will usually fix the problem in one go. For a deeper dive, see our guide on fixing AI writing that sounds too formal. **Related**: Why does AI writing sound so robotic? | How to create a custom writing style guide for ChatGPT?